Jian-Dong Huang, BaoZhong Zhang, Richard Yi-Tsun Kao, Konghung S Z E, Bo-Jian Zheng and Kwok-Yung Yuen
The Chinese University of Hong Kong, China
Posters & Accepted Abstracts: J Drug Metab Toxicol
Staphylococcus aureus (S. aureus) is a common pathogen found in the community and in hospitals. Most notably, methicillinresistant S. aureus is resistant to many antibiotics, which is a growing public health concern. The emergence of drugresistant strains has prompted the search for alternative treatments such as immunotherapeutic approaches. Prophylactic vaccination is the best approach to combat against MRSA since it can provide protection without any concerns regarding antibiotic resistance. To date, most clinical trials of vaccines or passive immunization against S. aureus have ended in failure. In this study, we investigated two ESAT-6-like proteins secreted by S. aureus, SaEsxA and SaEsxB, as possible targets for a vaccine. Mice vaccinated with these purified proteins elicited high titers of anti-SaEsxA and anti-SaEsxB antibodies, but these antibodies could not prevent S. aureus infection. On the other hand, rSaEsxA and rSaEsxB could induce Th1- and Th17- biased immune responses in mice. Mice immunized with rSaEsxA and rSaEsxB had significantly improved survival rates when challenged with S. aureus compared with the controls. These findings indicate that SaEsxA and SaEsxB are two promising Th1 and Th17 candidate antigens, which could be developed into multivalent and serotype-independent vaccines against S. aureus infection. We further included several other antigens to create a multi-component vaccine against several strains of S. aureus. Animal test indicated a protection rate over 90% in several animal models against multiple strains of S. aureus.
Email: jdhuang@hku.hk
